Apparatus for regulating the speed and power of internal-combustion engines.



H. R. RICARDO. APPARATUS FOR REGULATING THE SPEED AND POWER OF- INTERNAL COMBUSTION ENGINESL APPLICATION FILED FEB. 5.19M). 3QLQ'ZQD Patented Apr. 29, 1919.

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H. R. RICARDO. APPARATUS FOR REGULATING THE SPEED AND POWER OF INTERNAL COMBUSTION ENGINES.

APPLICATION FILED FEB. 5. I919 Patented Apr. 29, 1919.

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ABBY RALPH RICARDO, OF LONDON, ENGLAND.

- Tlb'S roa nneunarrne THE srnsn AND rowan or INTERNAL-COMBU salon enemas.

Application filed February 5, 1919. Serial No. 275,262.

To all whom it may concern Be it known that T, HARRY RALPH RI- CARDO, of 21 Suffolk street, Pall Mall, London, S. W., England, have invented certain new and useful Improvements in Apparatus for Regulating the Speed and Power of Internal-Combustion Engines, of which the following is a specification.

This invention relates to apparatus for regulating the speed and power of internal combustion engines more particularly those intended for use on aircraft and has for its object to provide mechanism whereby the time of closing the inlet valve or valves can be varied and will be determined by the varying density of the air.

According to this invention mechanism is provided which is operated by a liquid such as oil under pressure so as to alter the setting of a valve operating cam and the supply of the liquid under pressure to this mechanism is controlled by a valve which is actuated by a device which is sensitive to variations in the atmospheric pressure. The valve which controls the supply of liquid to the cam setting mechanism is a hunting valve and effects the control in such a manner as to permit this mechanism to set the cam and subsequently cause the cam to be retained in the position in which it has been set. The cam can be rotated relatively to the shaft on which it is mounted so as to alter its setting for the purpose of varying the time of closing of an inlet valve. Conveniently a piston which is moved in a cylinder by liquid under pressure serves to bring about the rotary setting of the cam and the hunting valve controls the supply of liquid to the cylinder. The cam is rotatably mounted on a hollow shaft Within which is disposed a member which is connected at oneend to the cam through the wall of the shaft while the end of the member which projects from the end of the shaft is connected to the piston which moves in its cylinder by liquid pressure in opposition to a spring. The hunting valve is actuated by a device sensitive to variations in atmospheric pressure and so controls the supply of liquid to the cylinder as to cause the piston to move and the cam to be set thereby and subsequently locked and retained in its set position by the liquid. The nature of the device which brings about the movement of the hunting valve consequent 'on the piston and cam is however limited so that while it is always possible by means of the hand control tobring about later closing of the inlet valve than is determined by the atmospheric control it is not possible Specification of Letters Patent. Patented Apr, 29, 1919. i

to cause the inlet valve to close earlier eX- cept to a small extent. The spring which acts on the piston tends to bring about such a setting of the cam as will cause the inlet valve tobe closed at the latest moment allowed by the mechanism so that in the event of either the atmospheric control device or the oil pressure system becoming inoperative the cam will automatically be set so as to close the inlet valve late and give the lowest compression in the cylinder thus insuring safety and obviating the risk of excessive compression occurring.

The invention may be put into practice in various ways but the accompanying drawings illustrate by way of example one construction that may be adopted in an engine intended for use on aircraft. In these drawings,

Figure 1 is a vertical sectional elevation through a part'of the cam shaft and one cylinder of an engine showing the improved regulating apparatus. ig. 2 is a transverse section through the cam shaft on the line 22 in Fig. 4.

Fig. 3 is a similar section on the line 3-3 in Fig. 4 looking in the direction of'the arrows. 1

Fig. 4 is a vertical section through cam shaft, showing inlet and exhaust cams.

Like letters indicate like parts throughout the drawings. The cams operating the inlet and exhaust valves are conveniently grouped together on a hollow cam shaft. Assuming that each cylinder of the engine is provided with two inlet valves and two exhaust valves the latter may conveniently be operated by two the inlet cam lies the third part'C of this cam which is separately rotatable and adjustable by ,means of a radially disposed pin C which extends from a tubular member D within the hollow cam shaft B through a slot B in the wall of this shaft and into a hole or recess in the adjustable cam part. The tubular member D which, is thus connected to the adjustable cam part C is arranged so as to be rotatable within the cam shaft B and this tubular member extends beyond the end of the cam shaft and has mounted on its end a transverse pin D which preferably carries toward its ends a pair of rollers D; On the end of the cam shaft B is a sleeveE which can slide in the axial direction on the cam shaft and this sleeve has formed in it two oppositely arranged helical slots E in which lie the rollers ,l) on the transverse pin D which is carried on the end of the cam setting member D, The helical slots E are formed with a quick pitch and act as a cam so that as the sleeve E is moved in the axial direction on the cam shaft B the cam setting member D will be rotated within the-cam shaft and relatively thereto.

The outer end E of the slotted sleeve .E E is attached to a piston F by a central pin F with a ball bearing interposed the piston being disposed in a cylinder G coaxially arranged with relation to the cam shaft B., The cylinder G is closed at one end G and its open end is directed toward the end of the cam shaft B. Between the piston F and a member H suitably mounted within the casing or framing and around the end of the cam shaft B is a coiledspring J which bears at one end against this fixed part. and at the other end against the outer face of the piston F, the spring I thus tending to move the piston toward the inner end G of the cylinder. By reason of the connection between the piston F and the slotted sleeve E E it will be seen that while this sleeve can rotate freely with the cam shaft B as the latter is driven by the engine in some convenient known manner as for instance by the bevel gear B B any movement of the piston in the cylinder G will cause the slotted sleeve to slide on the end of the cam shaft and rotate the'cam setting member D relativelytol the cam shaft and thus the setting of the cam C C will be altered and the time of closing of the inlet valves will be varied, The' formation of the adjustable art 0 of the cam G is such as to enab e the raised or o erative part of the cam to have its circum 'erential measurement increased or diminished according to the direction in which the adjust. able portion of the cam is moved as shown in Fig. The parts are so arranged; that when the piston F is in its extreme position adjacentto the closed end G of the cylinder G, into which position as indicated the spring J tends to move it as shown in Fig. 1, the adjustable part 0 of the cam C will be set so as to increase the circumferential length of the operative face of the cam to its maximum as shown in dotted lines in Fig. 2 with the result that the inlet valve will be held; open to the latest point determined. As the piston F moves outwardly in the cylinder G against the action of the spring J the circumferential length of the operative face of the cam C will be decreased until the limit of movement of the parts is reached when the inlet valve will be closed at the earliest determined movement.- The formation of the movable part C of the cam is conveniently such that when this occurs this movable part lies wholly within the limits of or coincides wholly with the fixed parts of the cam as shown in full lines in Fig. 2. v

The movement of the piston F in opposition to the spring J is brought about by passage G which leads from a port G 1n a small cylinder K arranged adjacent and parallel to the main cylinder G. In this small cylinder lies a piston valve conveniently constructed as follows. On a hollow rod L whose ends are open and toward one end thereof are formed two cylindrical enlargements L L separated by a suitable distance. One of these enlargements L which is situated nearest to the end of the hollow rod L which lies within the cylinder K carries a piston ring which may be held In lace by a ring screwed on to the end of the hollow rod. The dimensions of the enlargements L L constituting the operative part of the valve and the reduced partL between them are conveniently such that the to cover and completely close the port G leading to the main cylinder G while the a other enlargement L lies toward the outer end of the valve cylinder K and serves to close this end of the cylinder and prevent theoutfiow of oil which enters by an intermediate port K.. This inlet port K through which oil under pressure enters the neonate 33 part 0 of the cam will consequently also be locked and retained in the position into which it has been set by the movement of the piston F. If the piston valve L L is moved inwardly in its cylinder K the port G will be uncovered and oil under pressure will be free to flow from the inlet K pastthe valve into the main cylinder G and bring about a movement of the piston F. If the piston valve L L moves outwardly the port G is first covered again and then uncovered on the inner side of the enlargement L so that oil can escape from the main cylinder G into the inner end of the-valve cylinder K whence it passes through the hollow valve stem L and from the outer end thereof into the casing which incloses the mechanism. Thence this oil can drain away to a-sump for use again or not as desired.

The movement of the piston valve L" L is brought about in the following manner. A sliding rod M carried in a suitable guide N is mounted near and conveniently above the piston valve L L which in turn is disposed above the main ,cylinder G and this rodM can slide parallel to the piston valve rod L. One end M of the rod M passes out through the casing which forms the guide N and theother end M extends within the casing and is connected conveniently in an adjustable manner toa flexible diaphragm O which forms one wall of a closed chamber O of suitable shape and construction which is filled with air at the atmospheric pressure at ground level. A coiled spring P tends to move the rod M in the direction of, the diaphragm 0 this spring being disposed between the part N of the casing in which the rod slides and a collar M on the rod. Beyond this collar the end portion M of the rod M is screwthreaded and carries a sleeve M the position of'which in the axial direction of the rod can be adjusted by rotating the sleeve and the rod relatively to each other and locking them together in some suitable manner. The screwthreaded end M of the rod M engages a ball socket O mounted on the flexible diaphragm 0. By rotating the rod M and the socket O relatively the length of the rod and its relation with the diaphragm can be adjusted. Pivotally connected to the adjustable sleeve M is one end Q of a lever which is also pivoted at some point Q intermediate in its length to the end of the hollow piston valve rod L. The other end Q of this lever is slotted and engages a pin F carried on a bracket or arm F which extends from the main piston F. If convenient this lever Q Q may be duplicated.

The arrangement is such that if as a result of fluctuations in the density of the atmosphere the flexible diaphragm 0 moves outwardly toward the rod M and imparts slidlng movement thereto the lever Q Q will be turned about its pivotal connection F with the main piston F which then constitutes'a fulcrum and as a result the piston valve L L will be moved inwardly in its cylinder K. This will allow oil under pressure to-pass into the main cylinder G and effect movement of the piston F in the outward direction that is to say toward the end of the cam shaft B. As the end Q of the lever will now be held practically stationary this end will serve as a fulcrum and the lever will turn about this point as the piston F moves with the result that the piston valve L L will be moved outwardly again into a position such as to shut off the supply of oil to the cylinder G. The piston F will then be locked in the position into which it has moved and the cam part C having been set by the piston movement will also be locked in its set position. The parts will thus remain until they are again caused to move'by further variation in the'atmospheric pressure. If this pressure decreases movement in its cylinder under the influence of the spring J and as it moves it will again turn the lever about the end Q which is pivoted tothe sliding rod M.- This will cause the piston valve L L to move in* wardly and once more close the oil passage G so that further movement of the piston F will be stopped.

In order to permit the cam C C to be adjusted by hand a two-armed lever B R is pivoted at S on the outside of the casing adjacent to the cylinder G and piston valve L L One arm R of this lever is formed so as to lie between two collars M M or projections mounted on the outer end M of the sliding rod M the positions of these collars conveniently being adjustable. These collars M M are spaced at a distance apart which is so determined in accordance with the possible range of movement of the lever R R that limited movement only can be imparted in either direction to the sliding rod M by means of the lever. The other arm R of the lever'is adapted tobe moved by hand either directly convenient manner. The arrangement is such that at the ground level or when the atmospheric pressure is normal and the cam C C isset so as to close the inlet valve at the latest point and reduce the compression in the c hnder, by movement of the hand the inlet valve it is not then possible by means of the hand lever B R to move the sliding rod M and close the inlet valve still earlier if the rod has been moved so as to take one of the collars M M thereon, out of range of the end B of the hand lever. It is however then possible by means of this lever R R to move the rod M in the opposite direction against the action of the pres- Sure of the atmosphere in the closed chamber O acting on the flexiblediaphragm 0. Thus by means of the hand control the inlet valve can be closed later than may be determined by the atmospheric device but it Is not possible to close it earlier except within small limits and not at all if the atmospheric pressure is considerably reduced. 4

The details of construction may be varied to meet requirements and the type of engine to which the invention is applied.

What Iclaim as my invention and desire to secure by Letters Patent is 1 Lin an internal combustion engine the combination of an inlet valve, mechanism for operating this valve which is adjustable so as to vary the time of closing the valve, mechanism actuated by liquid under pressure and operative to adjust valve operating mechanism, a valve controlling the flow of liquid to and from this mechanism, and means for actuating this controlling valve.

in accordance with variations in the atmospheric pressure as set forth.

2. In an' internal combustion engine the combination of an inlet valve, a cam by means of which this valve is operated the cam being adjustable so as to vary the time of closing the valve, mechanism actuated by liquid under pressure and operative to adjust the cam, a valve controlling the flow of liquid to and from this mechanism, and

means for actuating this controlling valve in accordance w th variations in the atmosphericpressure as set forth.

3. In an internal combustion engine the combination of an inlet valve, a cam by means of which this valve is operated the cam being adjustable about the axis of the shaft on which it is mounted so as to vary or indirectly in some neonate the dimension of the operative portion of by liquid under pressure and operative to adjust the camon its shaft, a valve controlling the flow of liquid to and from this mechanism, and means for actuating this controlling valve'in accordance with variations in the atmospheric pressure as set forth.

4:. In an internal combustion engine the combination of an inlet valve, a cam by means of which the-valve is operated one part of this cam being fixed on the cam shaft while the other. part is adjustable about the axis of the shaft so as to vary the dimensions of the operative portion of the cam and correspondingly vary the time of closing the valve, mechanism actuated by liquid under pressure and operative to adjust the one part of the cam relatively to the other part, a valve controlling the flow of liquid to and from this mechanism, and means for actuating this controlling valve in accordance with variations in the atmospheric pressure as set forth.

5. In an internal combustion engine the combination of an inlet valve, mechanism for operating this valve which is adjustable so as to vary the time of closing the valve, mechanism comprising a cylinder containing a spring controlled piston actuated by liquid under pressure the piston being operative by its movementin the cylinder to adjust the valve operating mechanism, a valve controlling the flow of liquid to and from the cylinder of this mechanism, and means for actuating this controlling valve in accordance with variations in the atmospheric pressure as set forth.

6. In an internal combustion engine the combination of an inlet valve, mechanism for operating this valve whiclf is-adjustable so as to vary the time of closing the valve, mechanism comprising a cylinder containing a. spring controlled piston which is actuated by liquid under pressure, means for converting the reciprocating movement of the piston into a rotary movement which is imparted to the valve operating mechanism and effects the adjustment of this mechanism, a valve controlling the flow of liquid to and from the cylinder, and means for actuating this controlling valve in accordance with variations in the atmospheric pressure as set forth.

7. In an internal combustion engine the combination of an inlet valve, a cam by means of which this valve is operated the cam being adjustable so as to vary the time of closing the valve, mechanism comprising a cylinder containing a spring controlled piston actuated by liquid under pressure the piston being operative by its movment in the cylinder to adjust the cam, a valve con- 1 eonora trolligg the flow of liquid to and from the cylin er of this mechanism, and means for actuatin this controlling valve in accordance with variations in the atmospheric pressure asset forth.

8. In an internal combustion engine the combination of an inlet valve, a cam by means of which this valve is operated the ca m being adjustable about the axis of the shaft on which it is carried so as to vary the dimensions of the operative portion of the cam and correspondingly vary the time of closing of the valve, mechanism comprising a cylinder containing a spring controlled'piston which is actuated by liquid under pressure, means for converting the reciprocating movement of the piston into a rotary movement which is imparted to the cam so as to effect its adjustment, a valve controlling the flow of liquid to and from the cylinder, and means for actuating this controlling valve in accordance With Variations in the atmospheric pressure asset forth.

9. In an internal combustion engine the combination of an inlet valve, mechanism for operating this valve which Is adjustable so as to vary the time of closing of the valve, mechanism comprising a cylinder containing a spring controlled piston which is actuated by liquid under pressure the piston being operative by its movement in the cylinder to adjust the valve operating mechanism, a

valve controlling the flow of liquid to and from the cylinder of this mechanism, a device having a part which moves as a result of changes in the density of the atmosphere, and a connection between the valve and both the movable part of the sensitive device and the piston as set forth.

10. In an internal combustion engine the combination of an inlet valve, a cam by means of which this valve is operated the cam being adjustable about the axis of the shaft on which it is carried so as to vary the dimensions of the operative portion of the cam and correspondingly vary the time of closing of the valve, mechanism comprising a cylinder containing a spring controlled piston which is actuated by liquid under pressure, means for converting the reciprocating movement of the piston into a rotary movement which is imparted to; the cam so as to efiect its adjustment, a valve controlling the flow of liquid to and from the cylinder, a device having apart which moves as a. result of changes in the density of the atmosphere,

and a connection between the valve and both the movable part of the sensitive device and the piston as set forth.

In testimony whereof I have signed my name to this specification. Y

HAY RALPH meanne- 

